Known in the art is the use of injecting-dispensing devices of this type within the fields of foodstuffs, chemicals, agriculture, industry and, in particular, when two or more different liquids have to be supplied in pre-established proportions and preferably mixed before they are used.
The devices of this type currently have the disadvantage of having to have complex design and structural characteristics. These characteristics mean a larger number of parts subject to wear by friction, with the consequent breakdowns and repairs, at the same time implying high pressure drops in the mixture supplied. Such pressure drops reduce the performance of the injector. All these factors give rise to high cost in the manufacturing, maintenance and functioning of these devices.
For the purposes of this invention, and as an example of a specific application, reference will be made in what follows to a dispensed irrigation water injector device for agriculture. Said improved proportional volumetric injector-dispenser essentially comprises a chamber or cylinder with two main sections of different diameter, inside which moves a primary piston with various zones of different diameter, fitting with close fit in said cylinder sections and with the corresponding pressure-tight seals, forming between the two zones a large central chamber which leads into the indicated two main sections in the cylinder, which central chamber communicates with a liquid-inlet pipe, while the internal end of the lower-diameter section of the cylinder has another pipe for outlet of the dispensed liquid to the exterior, with the piston body being traversed longitudinally by a slide, and being provided moreover with a secondary cylinder throughout a tubular support and connected to the exterior through a check valve and a connecting teat for a liquid-inlet pipe that permits the sliding of a secondary piston whose stem extends through the interior of the tubular support and is attached by its end to the main piston.